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Knowledge graph by

Ciro Santilli 40 Updated 2025-07-16

Many people believe that knowledge graphs are a key element of AGI: Knowledge graph as a component of AGI.

Bibligraphy:

www.knowledgegraph.tech/ The Knowledge graph Conference

Knowledge graph as a component of AGI by

Ciro Santilli 40 Updated 2025-07-16

twitter.com/yoheinakajima/status/1759107727463518702 "smallest RAG test possible of an indirect relationship on a knowledge graph"
www.quora.com/Do-knowledge-graphs-bases-have-a-place-in-the-pursuit-of-artificial-general-intelligence-AGI-or-can-their-features-be-better-represented-in-a-learning-based-system "Do knowledge graphs / bases have a place in the pursuit of artificial general intelligence (AGI), or can their features be better represented in a learning-based system?"

Apache Jena CLI tools setup by

Ciro Santilli 40 Updated 2025-07-16

as per: users.jena.apache.narkive.com/T5TaEszT/sparql-tutorial-querying-datasets-error-unrecognized-option-graph

The CLI tools don't appear to be packaged for Ubuntu 23.10? Annoying... There is a package libapache-jena-java but it doesn't contain any binaries, only Java library files.

To run the CLI tools easily we can download the prebuilt:

sudo apt install openjdk-22-jre
wget https://dlcdn.apache.org/jena/binaries/apache-jena-4.10.0.zip
unzip apache-jena-4.10.0.zip
cd apache-jena-4.10.0
export JENA_HOME="$(pwd)"
export PATH="$PATH:$(pwd)/bin"

and we can confirm it works with:

sparql -version

which outputs:

Apache Jena version 4.10.0

If your Java is too old then then running sparql with the prebuilts fails with:

Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: arq/sparql has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:756)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:473)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
        at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:621)

Build from source is likely something like:

sudo apt install maven openjdk-22-jdk
git clone https://github.com/apache/jena --branch jena-4.10.0 --depth 1
cd jena
mvn clean install

TODO test it.

If you make the mistake of trying to run the source tree without build:

git clone https://github.com/apache/jena --branch jena-4.10.0 --depth 1
cd jena
export JENA_HOME="$(pwd)"
export PATH="$PATH:$(pwd)/apache-jena/bin"

it fails with:

Error: Could not find or load main class arq.sparql

DeepMind Lab by

Ciro Santilli 40 Updated 2025-07-16

github.com/deepmind/lab

github.com/deepmind/lab/tree/master/game_scripts/levels/contributed/dmlab30 has some good games with video demos on YouTube, though for some weird reason they are unlisted.

TODO get one of the games running. Instructions: github.com/deepmind/lab/blob/master/docs/users/build.md. This may helpgithub.com/deepmind/lab/issues/242: "Complete installation script for Ubuntu 20.04".

It is interesting how much overlap some of those have with Ciro's 2D reinforcement learning games

The games are 3D, but most of them are purely flat, and the 3D is just a waste of resources.

Human player test of DMLab-30 Collect Good Objects task by DeepMind (2018)

Source.

Video 2.

Human player test of DMLab-30 Exploit Deferred Effects task by DeepMind (2018)

Source.

Video 3.

Human player test of DMLab-30 Select Described Object task by DeepMind (2018)

Source. Some of their games involve language instructions from the use to determine the desired task, cool concept.

Video 4.

Human player test of DMLab-30 Fixed Large Map task by DeepMind (2018)

Source. They also have some maps with more natural environments.

Why is COVID-19 so serious in some people but not in others? by

Ciro Santilli 40 Updated 2025-07-16

There are a few possibilities:

genetics
- bibliography:
  - www.science.org/doi/10.1126/scitranslmed.abj7521 Identification of driver genes for critical forms of COVID-19 in a deeply phenotyped young patient cohort by Carapito et al. (2021)
state of the immune system based on disease history
age

Reproducible builds by

Ciro Santilli 40 Updated 2025-07-16

Reproducible builds allow anyone to verify that a binary large object contains what it claims to contain!

Bibliography:

X-10 Graphite Reactor by

Ciro Santilli 40 Updated 2025-07-16

This was an intermediate step between the nuclear chain reaction prototype Chicago Pile-1 and the full blown plutonium mass production at Hanford site. Located in the Oak Ridge National Laboratory.

Figure 2.
Workers loading Uranium into the X-10 Graphite Reactor with a rod
. Source.

X-inactivation by

Ciro Santilli 40 Updated 2025-07-16

epigenetics mechanism.

X-Inactivation and Epigenetics by WEHImovies (2012)

Source. Shows how this makes every female mammal a chimera.

Convert bytes to hex from Linux CLI by

Ciro Santilli 40 Updated 2025-07-16

no formatting;

Graphical user interface by

Ciro Santilli 40 Updated 2025-07-16

Data compression by

Ciro Santilli 40 Updated 2025-07-16

PostgreSQL by

Ciro Santilli 40 Updated 2025-07-16

PostgreSQL feels good.

Its feature set is insanely large! Just look at stuff like: stackoverflow.com/questions/1986491/sql-split-string-by-space-into-table-in-postgresql/1993058#1993058

Had a look at the source tree, and also felt good.

If Oracle is the Microsoft of database, Postgres is the Linux, and MySQL (or more precisely MariaDB) is the FreeBSD (i.e. the one that got delayed by legal issues). Except that their software licenses were accidentally swapped.

The only problem with Postgres is its name. PostgreSQL is so unpronounceable and so untypeable that you should just call it "Postgres" like everyone else.

PostgreSQL logging by

Ciro Santilli 40 Updated 2025-07-16

stackoverflow.com/questions/722221/how-to-log-postgresql-queries

Ubuntu 21.10 has a certain default level of logging by default to:

/var/log/postgresql/postgresql-13-main.log

but it does not log everything, only/mostly errors it seems.

Setting:

log_statement = 'all'

under:

/etc/postgresql/13/main/postgresql.conf

and then restarting the server:

sudo service restart postgresql

just works.

Realtime monitoring for long queries instead: stackoverflow.com/questions/8597516/app-to-monitor-postgresql-queries-in-real-time

Ciro Santilli's sport practice by

Ciro Santilli 40 Updated 2025-07-16

As a Brazilian, Ciro Santilli used to really love playing soccer (but not watching it), until he hurt his knee.

Playing soccer just feels amazing, because you are constantly running around, but with a more specific goal in mind: to get that ball into that goal!

Playing soccer was specially amazing in the flat wet sand beach of Santos. weekend, the sea, feet touching the sand, the sun going down, and your school mates next to you. Nirvana.

It is also true that under those conditions, the skin of your feet will get ripped off due to running on the slightly wet and flat sand no matter how thick it has become. But it is worth it.

Teams would often be slit between "the team with shirts vs the team without shirts", who would just take off their shirts. The two best players would take turns picking players into their teams, the first one to pick would be decided by odds and evens (par ou ímpar).

A pair of Havaianas, or Havaianas rip-offs, stuck into the sand, or even just some school bags, would do as a goal posts. More organized people, especially adults, would have their own water pipe goal with a proper net and all. But doing so would spoil the fun of endless discussions if a non flat ball had gone in or not into an imaginary rectangle.

That's how soccer was meant to be played.

Ciro became however disillusioned with soccer after his injury. It is a shame.

And so after that, Ciro decided to dedicate himself to sports where you can't hurt your knee.

Ciro hates water, so swimming is out of the question. What could be more boring than going back and forth on a fixed location a million times to gain some milliseconds?

And so Ciro has been left with the gym as the only main option for a while.

Running would have been a consideration, but Ciro Santilli's legs sometimes itch when he runs.

This is until he ended up living in a place with decent roads for cycling in the late 2010's, which led to Ciro Santilli's cycling.

Adults playing soccer in Santos, São Paulo, Brazil beach on a rainy day

. Source. It is still warm though as you can see from their clothing.

Ciro Santilli's ancestors by

Ciro Santilli 40 Updated 2025-07-16

Where most of Ciro Santilli's ancestors came from, and why Ciro has the Italian nationality as well as Brazilian.

More specifically his paternal line comes from Gissi in the Abruzzo region.

Ciro feels really bad by the fact that he does not speak Italian and has never visited Gissi as of 2020.

He would likely be able to learn Italian in like 3 months because it is so similar to Portuguese and French which he already speaks.

And a cycling visit maybe? That would be amazing! en.wikipedia.org/wiki/Giro_d'Abruzzo | www.youtube.com/watch?v=OW7wqa3vNU8&list=UU35qUU5iZPvuzcre43EV8bA&index=25

For what it is worth though, Ciro Santilli does honestly love Europe, and feels a strong desire to make it even awesomer, along with the rest of the world. Despite this being a hopeless attempt due to having more than one natural language is bad for the world.

SQL application by

Ciro Santilli 40 Updated 2025-07-16

nodejs/sequelize/raw/parallel_create_delete_empty_tag.js by

Ciro Santilli 40 Updated 2025-07-16

In this example, posts have tags. When a post is deleted, we check to see if there are now any empty tags, and now we want to delete any empty tags that the post deletion may have created.

If we are creating and deleting posts concurrently, a naive implementation might wrongly delete the tags of a newly created post.

This could be due to a concurrency issue of the following types.

Failure case 1:

thread 2: delete old post
thread 2: find all tags with 0 posts. Finds tag0 from the deleted old post which is now empty.
thread 1: create new post, which we want to have tag tag0
thread 1: try to create a new tag tag0, but don't because it already exists, this is done using SQLite's INSERT OR IGNORE INTO or PostgreSQL's INSERT ... ON CONFLICT DO NOTHING
thread 1: assign tag0 to the new post by adding an entry to the join table
thread 2: delete all tags with 0 posts. It still sees from its previous search that tag0 is empty, and deletes it, which then cascades into the join table

which would result in the new post incorrectly not having the tag0.

Failure case 2:

thread 2: delete old post
thread 2: find all tags with 0 posts
thread 1: create new post
thread 1: try to create a new tag tag0, but don't because it already exists
thread 2: delete all tags with 0 posts. It still sees from its previous search that tag0 is empty, and deletes it
thread 1: assign tag0 to the new post

which leads to a foreign key failure, because the tag does not exist anymore when the assignment happens.

Failure case 3:

thread 2: delete old post
thread 1: create new post, which we want to have tag tag0
thread 1: try to create a new tag tag0, and succeed because it wasn't present
thread 2: find all tags with 0 posts, finds the tag that was just created
thread 2: delete all tags with 0 posts, deleting the new tag
thread 1: assign tag0 to the new post

which leads to a foreign key failure, because the tag does not exist anymore when the assignment happens.

Sample executions:

node --unhandled-rejections=strict ./parallel_create_delete_empty_tag.js p 9 1000 'READ COMMITTED': PostgreSQL, 9 tags, DELETE/CREATE the tag0 test tag 1000 times, use READ COMMITTED
Execution often fails, although not always. The failure is always:
```
error: insert or update on table "PostTag" violates foreign key constraint "PostTag_tagId_fkey"
```
because the:
```
INSERT INTO "PostTag"
```
tries to insert a tag that was deleted in the other thread, as it didn't have any corresponding posts, so this is the foreign key failure.
TODO: we've never managed to observe the failure case in which tag0 is deleted. Is it truly possible? And if not, by which guarantee?
node --unhandled-rejections=strict ./parallel_create_delete_empty_tag.js p 9 1000 'READ COMMITTED' 'FOR UPDATE': do a SELECT ... FOR UPDATE before trying to INSERT.
This is likely correct and the fastest correct method according to our quick benchmarking, about 20% faster than REPEATABLE READ.
We are just now 100% sure it is corret becase we can't find out if the SELECT in the DELETE subquery could first select some rows, which are then locked by the tag creator, and only then locked by DELETE after selection. Or does it re-evaludate the SELECT even though it is in a subquery?
node --unhandled-rejections=strict ./parallel_create_delete_empty_tag.js p 9 1000 'REPEATABLE READ': repeatable read
We've never observed any failures with this level. This should likely fix the foreign key issue according to the PostgreSQL docs, since:
- the DELETE "Post" commit cannot start to be seen only in the middle of the thread 1 transaction
- and then if DELETE happened, the thread 1 transaction will detect it, ROLLBACK, and re-run. TODO how does it detect the need rollback? Is it because of the foreign key? It is very hard to be sure about this kind of thing, just can't find the information. Related: postgreSQL serialization failure.
node --unhandled-rejections=strict ./parallel_create_delete_empty_tag.js p 9 1000 'SERIALIZABLE': serializable
node --unhandled-rejections=strict ./parallel_create_delete_empty_tag.js p 9 1000 'NONE': magic value, don't use any transaction. Can blow up of course, since even less restrictions than READ COMMITTED

All executions use 2 threads.

Some theoretical notes:

Failure case 3 is averted by a READ COMMITTED transaction, because thread 2 won't see the uncommitted tag that thread 1 created, and therefore won't be able to delete it

stackoverflow.com/questions/10935850/when-to-use-select-for-update from SELECT FOR UPDATE also talks about a similar example, and has relevant answers.

Black Hat Briefings by

Ciro Santilli 40 Updated 2025-07-16

Multi-factor authentication by

Ciro Santilli 40 Updated 2025-07-16

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